Indoor air quality in schools has been an issue since before the pandemic and now some teachers and parents feel like they have to build their own air filters to keep kids safe.
STEVE INSKEEP, HOST:
Students are returning to school in this country just as the delta variant surges. And that has some parents concerned about air quality in classrooms.
Here’s Gabrielle Emanuel of member station GBH.
GABRIELLE EMANUEL, BYLINE: Hillary Creech of Jonesboro, Ark., had an unusual back-to-school shopping list this year. She ordered a box fan, some high-quality air filters and a lot of duct tape, all to make a homemade air purifier to go in the local high school where her husband teaches and her son’s a 10th grader.
HILLARY CREECH: My husband’s classroom in particular has a wall full of windows, none of which open.
EMANUEL: Creech is an emergency room nurse practitioner. She says she’s been treating a lot of teenagers in the current COVID surge. And since the virus transmits more easily in poorly ventilated spaces, she’s been worrying about students piling into a classroom.
CREECH: It’s probably one of the first things I think about when I wake up. It is definitely one of the thoughts I have to try and turn off when I’m going to sleep.
EMANUEL: To quiet her worries, Creech looked up a picture she’d seen months earlier of a DIY, do-it-yourself, air purifier. And she built it last week, the day before her son returned to school.
DON BLAIR: It looks like a sort of janky (ph) box that has four sides made out of these standard air filters. And the top of the box is a 20-inch box fan.
EMANUEL: That’s Don Blair, a citizen scientist in the Boston area. He’s been pulling together resources and making step-by-step instructions to help parents and teachers build this box. The idea is simple. The fan sucks air through the filters, effectively cleaning it of particles the virus might be floating along on. Experts say filters with a so-called MERV 13 rating or better are ideal.
BLAIR: It probably takes about 10 or 20 minutes, really, to just assemble these things and tape them up. And if you do goof up, then no problem. It’ll take you 30 minutes.
EMANUEL: The whole thing is the size of a minifridge. And it lasts all school year. The parts cost somewhere between $70 and $120.
BLAIR: Now I’m going to put it on the highest setting.
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EMANUEL: Its official name is the Corsi-Rosenthal Box.
RICHARD CORSI: My name is Richard Corsi, and I am the incoming dean of engineering at the University of California, Davis.
EMANUEL: Corsi had the idea one day last year and posted it on Twitter. Within 24 hours, Jim Rosenthal, another air quality expert, built the box. Soon it took off. Corsi has had a 30-year academic career with tons of publications and millions of dollars in research. But this box, he says, is probably the most significant thing he’s done. A lot of people have been testing the boxes and getting good results.
CORSI: People are now reporting 600 cubic feet per minute as clean air delivery rates. That’s phenomenal. That’s actually better than a lot of the more expensive HEPA-based portable air cleaners.
EMANUEL: That means a lot, since HEPA filters are considered the gold standard. And Corsi is a big advocate, since air purifiers with HEPA filters can be plugged in anywhere. Many schools have bought these and other well-studied air cleaners. But they are expensive. And Corsi worries about the school districts that aren’t doing anything or are turning to solutions that haven’t been proven.
CORSI: We have almost no information about a lot of technologies that are being heavily marketed to school districts right now. They haven’t been rigorously tested.
EMANUEL: And there’s another big challenge. There’s no national requirement for schools to keep their air clean. And there’s no oversight. Last year, a study from the Government Accountability Office found that tens of thousands of schools across the country had heating, ventilation and air conditioning systems that needed attention. And that was before considering COVID.
For NPR News, I’m Gabrielle Emanuel.
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